1. Field of the Invention
The present invention relates to a buffered rotary valve, and more particularly, to a buffered rotary valve in which a buffer is additionally installed in a rotary valve to supply a fluid of high pressure and a fluid of low pressure, being input from a compressor, to a freezer, thereby reducing the amount of fluid being supplied and unnecessarily consumed, and enhancing the efficiency of a freezing system.
2. Description of the Related Art
Generally, a rotary valve is a device used to supply a gas of high pressure and a gas of low pressure, being generated in a compressor, to a freezer, by periodically alternating the gas of high pressure and the gas of low pressure. A rotary valve is used as a constituent of a regenerative extreme low temperature freezer, such as a Gifford-MacMahon (GM) freezer or a GM pulse tube freezer.
FIG. 1 is a schematic view showing the structure of a conventional rotary valve, FIG. 2 is a perspective view illustrating a valve seat of the conventional rotary valve, FIG. 3 is a perspective view illustrating a valve head of the conventional rotary valve, and FIG. 4 includes a block diagram illustrating a freezing system using the conventional rotary valve.
FIG. 1 illustrates an operational structure of a rotary valve. Generally, a rotary valve comprises four constituents, such as a valve head 1, a valve seat 2, a driving motor 3 and a pressure container 4, as illustrated in FIG. 1. The pressure container includes three exterior ports, such as a high pressure port 4a, a low pressure port 4b and a pulse pressure port 4c. The high pressure port 4a and the low pressure port 4b are connected to an outlet and an inlet of a compressor, respectively, and the pulse pressure port 4c is connected to a freezer.
In the interior structure of the pressure container 4, the high pressure port 4a is connected to an empty space with the driving motor 3 inside the pressure container 4 and is filled with high pressure fluid, and the low pressure port 4b is connected to a low pressure path 5 formed in the valve seat 2 and fills the low pressure path 5 with low pressure fluid.
As illustrated in FIG. 2, the valve seat 2 includes the low pressure path 5 and output paths 6 being connected to the pulse pressure port 4c. As illustrated in FIG. 3, the valve head 1 includes high pressure grooves 7, a low pressure groove 8, and a motor shaft receiver 9 so that the valve head 1 is connected to the driving motor 3.
The valve head 1 is connected to the driving motor 3 by the motor shaft receiver 9 and is rotated on the valve seat 2 by the driving motor 3, thereby alternately supplying the high pressure fluid and the low pressure fluid to the output paths 6 formed in the valve seat 2. The aforementioned process will be described in detail as follows. When the high pressure grooves 7 of the valve head 1 are exposed to the high pressure fluid in the pressure container 4, the valve head 1 supplies the high pressure fluid through the output paths 6 and is rotated 90 degrees by the motor 3. Then, the high pressure grooves 7 of the valve head 1 are covered by the valve seat 2 and the low pressure groove 8 of the valve head 1 connects to the low pressure path 5 of the valve seat 2 and the output path 6 of the valve seat 2, thereby supplying the low pressure fluid to the freezer.
Referring to FIGS. 4A and 4B, the pressure and the amount of fluid being supplied from a rotary valve 11 connected with a compressor 10 to the freezer as shown in FIG. 4A are observed as shown in FIG. 4B. While the pressure is momentarily changed, a great amount of fluid is generated between the rotary valve 11 and the freezer, and this momentary fluid pulse does not contribute to the freezing of the freezer. Accordingly, in view of thermodynamics, since the mass of the gas supplied from the compressor 10 is not entirely used in the freezer, the entire efficiency of the freezer decreases.